ANGIOSPERM WOOD FROM THE UPPER CRETACEOUS OF CENTRAL CALIFORNIA: PART II

Three species of fossil wood representing two genera are described. The specimens are from a collection of woods from the Upper Cretaceous Panoche formation of central California. Tetracentronites panochetris sp. nov. resembles angiosperm wood in ray structure and vascular pitting but lacks vessels. Plataninium platanoides sp. nov. is similar to the wood of Platanus, and the evidence presented points to a direct relationship. The resemblance between Plataninium cali-fornicum sp. nov. and the woods of certain Icacinaceae is discussed, but evidence of relationship is inconclusive.     

ANGIOSPERM WOOD FROM THE UPPER CRETACEOUS OF CENTRAL CALIFORNIA: PART I

This paper is the first in a series about a collection of 40 Upper Cretaceous woods from central California. The wood is in the form of fragments of stems and roots embedded in nodules of collophane rich in microorganisms, pollen, and spores. Two new species are described: Ulminium pattersonensis and Ulminium mulleri. Evidence presented indicates that these two specimens are similar to woods of the Lauraceae and fall well within the range of variation of woods of that family. Because the taxonomy of the Lauraceae is in need of revision, meaningful comparisons of fossil plant parts with modern taxa were found to be unfeasible.     

ANGIOSPERM WOOD FROM THE UPPER CRETACEOUS OF CENTRAL CALIFORNIA. III

Five species representing five genera are described. The specimens are part of a collection of woods from the Upper Cretaceous Panoche Formation of central California. Lardizabaloxylon cocculoides sp. n. resembles wood of those species of Cocculus of the Menispermaceae lacking included phloem. Carpinoxylon ostryopsoides sp. n. is similar to the wood of the Coryleae of the Betulaceae, particularly Ostryopsis. Riboidoxylon cretacea gen. et sp. n. is similar to the wood of Ilex of the Aquifoliaceae and also falls within the range of variation of the woods of the two closely related families, the Grossulariaceae and the Escalloniaceae. Mulleroxylon eupomalioides sp. n. falls well within the range of variation of the woods of the Magnoliaceae.     

长叶榧的木材结构

<正> 所用木材标本采自福建省太宁县。树干胸径为10.5厘米。在横切面上,从中心向外连续选取木材样品两个,照一般方法作横向、径向和弦向三种切片租离析,均用番红染色,供显微研究使用。     

TAXODIACEOUS BARK FROM THE UPPER CRETACEOUS OF ALBERTA

The structure of a piece of silicified bark of Taxodioxylon gypsaceum from near Medicine Hat in Southern Alberta is described. The fossil specimen probably came from Upper Cretaceous beds. The fossil shows affinities with the bark of modern Sequoia. Vectia luccombensis Stopes (1915) from the Lower Greensand (Aptian) of England probably constitutes an isolated piece of taxodiaceous bark, similar to the inner bark of the Alberta specimen.     

CHLORANTHUS-LIKE STAMENS FROM THE UPPER CRETACEOUS OF NEW JERSEY

Fossil angiospermous stamens with in situ pollen from the Turonian (ca. 90 million years before present, Late Cretaceous) of New Jersey are described and assigned to the Chloranthaceae. The fossil stamens, which are three-parted and bear two bisporangiate thecae on the central lobe and one bisporangiate theca on each lateral lobe, are indistinguishable from stamens of several extant species of Chloranthus. The pollen is spheroidal, 13–18 μm in diameter, with a reticulate exine and apparently elongate/elliptical apertures. The pollen is similar to that in extant Chloranthus in grain size, shape, exine sculpture, and aperture structure. Like pollen of some extant species of Chloranthus, aperture number in the fossil pollen appears to be variable. Because fossil pistillate chloranthoid reproductive structures have not been found at this locality it is unknown whether the fossil stamens described here were borne on the side of the ovary, as in extant Chloranthus, or in another arrangement. The three-parted stamen of Chloranthus is unique in angiosperms and there has been considerable debate concerning the origin and evolutionary significance of the structure. Uncertainty as to whether the three-parted stamen represents a synapomorphy for the genus or a retained plesiomorphy in angiosperms is the primary reason why these fossil stamens are not assigned to the extant genus Chloranthus.     

PERMINERALIZED PINACEOUS LEAVES FROM THE UPPER CRETACEOUS OF HOKKAIDO

Three fragments of fascicles of a possible five-needle pine are described from the Upper Cretaceous Yezo Group (Santonian/Senonian) of Hokkaido. Specimens from the Omakizawa, Oyubari, Yubari City, the Koyanozawa, Ikushumbetsu, Mikasa City, and the Sankebetsugawa, Haboro are preserved in calcium carbonate nodules containing abundant ammonites. Leaves borne in apparent fascicles of five measure 0.7–0.8 mm in radial and 0.8–1.0 mm in tangential diam and are represented by short fragments of isolated needles. Thick-walled epidermal cells on these amphistomatic leaves resemble the underlying uniform hypodermis. Two external resin canals are situated near the lateral corners toward the adaxial surface. Only slightly plicate mesophyll cells in a layer one to two cells thick border on an elliptical endodermis with thickened outer cell walls. Two to three layers of transfusion tissue surround the double vascular strand. Two vascular bundles are separated by one cell layer of sclerenchyma fibers. Small patches of abaxial and adaxial sclerenchyma fibers have also been observed. Leaves most closely resemble those of Pinus leiophylla Schl. et Cham. Subgenus Pinus, Section Pinea, Subsection Leiophyllae and P. montezumae Lamb. Subgenus Pinus, Section Pinus, Subsection Ponderosae and are described as a new species P. hokkaidoensis sp. nov. Stockey and Ueda. Close anatomical comparisons are made with this leaf and previously described permineralized Upper Cretaceous pine needles from Hokkaido and eastern North America.     

A NEW CONIFER FROM THE UPPER CRETACEOUS OF CENTRAL CALIFORNIA

Stems with inner bark, wood, pith, and leaves from the Upper Cretaceous (Maastrichtian) of central California are described. The name Margeriella cretacea gen. et sp. n. is assigned to the fossils. The leaves are long, narrow, spirally arranged, and each contains three resin canals, a thick vascular sheath, and a dense mesophyll. Only first-year wood is present in the stem. The large pith is composed of large cells among which are scattered clusters of even larger darkly colored cells. Leaf epidermis and wood characters suggest affinities with the Taxodiaceae, but the structure of the pith and the internal structure of the leaves have no counterpart among modern or known fossil members of that family. The fossil is regarded as an extinct form possibly belonging to the large taxodioid complex thought by some workers to have existed in the Mesozoic.     

PINUS TRIPHYLLA AND PINUS QUINQUEFOLIA FROM THE UPPER CRETACEOUS OF MASSACHUSETTS

Dwarf shoots and needle leaves of Pinus triphylla Hollick and Jeffrey and P. quinquefolia Hollick and Jeffrey have been discovered recently in a Late Cretaceous age clay deposit on Martha's Vineyard Island, Massachusetts. Detailed study of these fossils provides further information on the internal construction of the two taxa. This new information permits both species to be compared easily with similar fossil forms from the Upper Cretaceous of Japan as well as with dwarf shoots and needles of modern species of Pinus. As a result, the relationships between Cretaceous pines and the extinct genus Prepinus are found to be less than previously believed. Moreover, the dwarf shoots and needles of Cretaceous members of the genus Pinus appear to be most like those of present-day species included in the subgenus Pinus.     

广西合浦盆地晚白垩世和古新世的介形类化石

本文报道合浦盆地晚白垩世乌家组和古新世上洋组的介形类化石14属23种(描述1新种),可划分两个化石组合:(1)Rhombicypridea quadrata-Heterocypris hepuensis-Limnocythere sinuata组合,属于Talicypridea动物群,产于乌家组,时代为晚白垩世;(2)...     

NEW TAXODIACEOUS SEED CONES FROM THE UPPER CRETACEOUS OF NEW JERSEY

Nephrostrobus cliffwoodensis gen. et sp. nov., Nephrostrobus bifurcatus sp. nov., and Rhombostrobus cliffwoodensis gen. et sp. nov. are described based on anatomical studies of seed cone fragments from the Upper Cretaceous Magothy Formation of New Jersey. These species belong to the Taxodiaceae. As in Sequoia, Sequoiadendron. and Metasequoia, the vascular strands supplying the scale and bract in Nephrostrobus are about equal. These vascular strands are arranged in a reniform pattern resembling that found in Metasequoia, but the orientation differs by 180 degress. Nephrostrobus cliffwoodensis and Nephrostrobus bifurcatus differ from each other in the branching of the complex trace and associated resin canals. Rhombostrobus cliffwoodensis resembles Cunninghamia in the arrangement of vascular strands and associated resin canals in its bract-scale complexes. However, the relative amount of bract and ovuliferous scale making up the complex is more like that in Sequoia. This combination of cone features does not occur in any of the extant genera. Nephrostrobus and Rhombostrobus are not considered to be ancestral to any of the extant taxodiaceous genera, but are extinct members of an ancestral complex from which the extant genera were derived.     

中国上白垩统窃蛋龙科一新属种(兽脚类:窃蛋龙类)(英文)

根据可能发现于江西赣州晚白垩世南雄组地层中一件标本报道了窃蛋龙科一新属种——斑嵴龙。新标本具有以下不同于其他窃蛋龙属种的特征:由前颌骨和鼻骨形成的脊冠具有阶梯状的后端,表面有两个纵向的沟槽和许多倾斜的条痕;外鼻孔延长,其后侧与眶骨相近;翼骨腭骨支背缘有一深窝;齿骨后背缘有纵向沟槽;上隅骨前背缘有小结节。斑嵴龙腭部和下颌的一些特征不同于窃蛋龙科的其他属种,但近似于更原始的窃蛋龙类。这些特征表明斑嵴龙代表窃蛋龙科中相对原始的一个属种。这一系统发育假说得到了定量的系统发育分析的支持。斑嵴龙的发现不仅增加了晚白垩世窃蛋龙科的分异度,而且为这一类群的特征演化提供了重要信息。     

A NEW ELASMOSAURID PLESIOSAUR FROM THE UPPER CRETACEOUS OF FUKUSHIMA, JAPAN

Abstract:  A new genus and species of an elasmosaurid plesiosaur, Futabasaurus suzukii , is described based on a partial skeleton from the Inoceramus amakusensis Zone (Lower Santonian, Upper Cretaceous) of the Irimazawa Member of the Tamayama Formation, Futaba Group, in Fukushima Prefecture, Japan. The new taxon is characterized by a number of characters such as the wide space between the orbit and external naris, posterior extension of the interclavicle, relatively long humerus and prominent femoral muscle scar. The holotype includes a partial skull and mandible, posterior cervicals to sacrals, ribs, clavicular arch, pelvic girdle and four limbs. The remains are mostly in articulation, and exhibit evidence of predation/scavenging by sharks. The distribution of elasmosaurid species in the circum-Pacific region remains unclear due to the lack of diagnostic materials. The occurrence of F. suzukii is geographically and stratigraphically significant, because it allows species-level comparison; as a diagnosable elasmosaurid specimen, F. suzukii is the first and the oldest from the northern Pacific.     

NEOSELACHIANS FROM THE UPPER CAMPANIAN AND LOWER MAASTRICHTIAN (UPPER CRETACEOUS) OF THE SOUTHERN PYRENEES, NORTHERN SPAIN

Abstract: Bulk sampling of upper Campanian to lower–middle Maastrichtian coastal and lagoonal deposits in five sections of the Tremp Formation in the south‐central Pyrenees yielded numerous neoselachian teeth. The fauna comprises nine taxa of which three species and one genus are new: Hemiscyllium sp., Lamniformes indet., Paratrygonorrhina amblysoda gen. et sp. nov., Coupatezia trempina sp. nov., Coupatezia sp., Coupatezia? sp., Rhombodus ibericus sp. nov. and Igdabatis indicus. The neoselachian fauna is dominated by small nectobenthic rays. This composition resembles assemblages known from the marine Upper Cretaceous, but differs from nearby localities of the Basque‐Cantabrian region and continental selachian associations of the French Pyrenees. The results indicate that Rhombodus might not be a reliable biostratigraphic marker for the Maastrichtian. The faunal composition suggests a shallow trans‐Tethyan connection between Eurasia and India at the end of the Cretaceous Period.     

香榧营养苗端细胞组织分区的超微结构观察

本文研究了榧树(Torreya grandis)成熟植株在季节生长中营养苗端的超微结构变化。各区域细胞的主要区别特征为:顶端原始细胞与亚顶端细胞相接的细胞壁较厚,液泡多分布于细胞游离面,质体中淀粉粒较小;亚顶端细胞壁较厚,液泡较大,质体中淀粉粒较大而多;周缘区细胞质体多不具淀粉粒,液泡也较小,胞间连丝丰富;肋状区细胞被大量的含淀粉质体及液泡占据了大部分空间,胞间连丝丰富。在季节变化的四个时期中,各区域细胞的亚显微结构特征亦不相同。休眠期各区细胞淀粉质体较发达,细胞壁较厚,液泡大;叶扩展期淀粉质体减少或消失;芽鳞形成期出现大量小液泡;新的顶芽形成期液泡增加,核糖体含量较高。讨论了各区域细胞核形态与其细胞活跃性的关系。     

黑龙江嘉荫晚白垩世渔亮子组孢粉地层研究

黑龙江嘉荫县渔亮子组是我国最早发现爬行动物化石的层位,盛产鸭嘴龙等爬行类化石,前人认为,该组在层位上相当于北美晚白垩世马斯特里赫特期Ｅｄｍｏｎｔｏｎ群,ＨｅｌｌＣｒｅｅｋ和Ｌａｎｃｅ组,但孢粉化石资料提示,渔亮子组中的被子植物花粉尚未发展至上述群（组）的阶段,其层位应较之低,大致相当于北美的坎佩尼期ＢｅｌｌｙＲｉｖｅｒ群（组）或相当层位。     

松辽盆地晚白垩世介形类古生态学

通过化石组合和岩性指标分析松辽盆地上白垩统自下而上青山口组—姚家组—嫩江组一段介形类的古生态学。青山口组盐度具有偏咸性、微咸性到半咸性的变化,32个介形类种以栖居于温暖湿润气候带的浅湖微咸水类型占绝对优势,水体清澈安静,有机质丰富,底质为泥等细粒沉积物(个别的为粉砂沉积物),宜于介形类动物群生长且有利于壳体完好保存;其次为生活于半咸水的深湖—半深湖类型,底质为泥。姚家组—嫩江组一段见23个介形类种,栖居于温暖半湿润气候带,以半咸水的深湖、半深湖—浅湖区的类型为主,多泥底,偶见粉砂质底;其次为微咸水的浅湖—三角洲前缘型,泥或粉砂质底;仅3个种生活于温暖湿润的粉砂质底淡水浅湖区。温暖湿润的淡水三角洲分流平原带则难以产出介形类化石。     

A NEW SCIADOPITYACEOUS SEED CONE FROM THE UPPER CRETACEOUS OF HOKKAIDO,JAPAN

A sciadopityaceous seed cone, Sciadopityostrobus kerae, gen. et sp. nov., is described on the basis of a permineralized specimen from the Upper Cretaceous (Cenomanian–Coniacian) of Hokkaido, Japan. The peel method was applied for anatomical observations. The seed cone consists of a cone axis receiving numerous cone scale complexes that are arranged helically. Each complex generally has five inverted ovules that are oriented adaxially. The cone is similar to those of living Sciadopitys verticillata with respect to its peltate cone scale complex, with free apices of both bract and ovuliferous scale, trichomes on the bract, and a trifurcated ovuliferous scale strand. In the fossil, the bract and ovuliferous scale strands fuse with each other in the basal part of the cone scale complex, while S. verticillata bract and ovuliferous scale strands are derived separately from the vascular cylinder and remain separate throughout their length. The present specimen is one of the oldest records of structurally preserved cones that can be assigned to the family Sciadopityaceae.